New Design Tool Analyzes Cost of Operating a Building Over its Lifetime

Golden, Colo., August 2, 2002

Imagine being able to estimate the energy
life-cycle costs of a new building by simply entering numbers into a
software program. Thanks to the new Energy-10 design tool, this is now
possible.

The new software - Energy-10 Version 1.5 - is an upgrade to the original
program developed at the U.S. Department of Energy's (DOE) National
Renewable Energy Laboratory (NREL).

The new Energy-10 contains seven upgrades including a discounted cash-flow
evaluation of a building over its lifetime and a more powerful graphing
package. The cash-flow evaluation of a building is determined and discounted
to the present value taking into consideration such factors as the initial
cost of construction, mortgage payments, annual electric costs and annual
tax benefits. Costs can be estimated using simple scaling laws or users can
supply their own cost estimates.

"Energy-10 allows the user to play 'what if' games while designing a
building or home," said Energy-10 author Doug Balcomb, research fellow at
NREL. "What if I change the windows? What if I add in energy efficient
equipment? What if I let the daylight in and turn down the lights?"

Helping architects and engineers understand the energy implications of their
work is critical in any strategy to reduce greenhouse gas emissions and
global warming. The life-cycle cost feature helps the designer make the case
for incorporating energy efficiency features by evaluating their cost
effectiveness, which is usually very positive.

Energy-10 now has 2,061 registered users and has been licensed to 60
colleges and universities where it is being used as a teaching tool for
architects and engineers.

Energy-10 allows an architect to watch a detailed simulation of how his
building will use energy and shows ways to reduce energy consumption. The
software simulates a year of hour-by-hour operations, a process that
requires about one billion calculations in a few seconds and displays
annual, monthly or hour-by-hour energy performance graphs.

The software incorporates detailed historical weather data for 239 locations
around the country, expandable to 3,945 locations, enabling architects to
accurately match their building with a site's weather patterns.

Energy-10 Version 1.5 is the result of collaboration among NREL, Lawrence
Berkeley National Laboratory and the Berkeley Solar Group. It is being
distributed by the Sustainable Buildings Industry Council (SBIC) in
Washington, D.C., which also provides training workshops and user support.
SBIC can be reached at 202-628-7400, ext. 210.